Data Quality Monitoring of the CMS Silicon Strip

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Data Quality Monitoring of the CMS Silicon Strip Tracker Detector Leonardo Benucci - University

Data Quality Monitoring of the CMS Silicon Strip Tracker Detector Leonardo Benucci - University of Antwerp, Belgium Data Quality Monitoring (DQM)) is being built to provide complete and coherent monitoring data (online and offline) at low latency, to ensure the optimal working of the hardware and software and to certify the quality of the data for analysis in an efficient way CMS SILICON STRIP (Si. Strip) TRACKER LAYOUT. . . quite a complex object: m 2 ≈ 200 m of Silicon sensors (the largest Si tracker ever built) ≈ 9. 3 million readout channels 15, 148 modules 4 different subdetectors CERTIFICATION PROCEDURE DQM ONLINE operates @ Point 5 (CMS site) DQM OFFLINE DATA from HLT and Storage Manager prepare Tracker flag on data quality before storage use Full statistic and a first calibration Manual + Automatic, operates @ Tier 0/1 - within few days operates @ Tier 0/1 - within day/hours during data taking DATA WHAT DQM MONITORS (Monitor Elements, ME): RAW data (readout and unpacking errors) DIGIS and Cluster (related or not to a track) track parameters Hit residuals Data Bookeeping System DATA (data for Physics) HOW DQM MONITORS: Producers (source) book and fill ME Consumers (client) access ME and produce Summaries to merge informations from each histogram of each module Quality tests: compare with reference histograms or reference values (mean, rms etc. ) generate 3 (adjustable) alarm levels visualize with Graphical User Interface (GUI) → CMS DQM GUI is web based: it is accessible from everywhere a web browser is available “Tracker Map” view Layout for shifters in DQM GUI Tracker-specific GUI Overall Tracker status Trend plots (Historic DQM) ONLINE: Monitor a reduced set of data OFFLINE: Analyze the full statistic Merge informations together status identify problems very efficiently during data collection to take prompt actions reconstruction and best calibration constante spot reconstruction, calibration or other unexpected problems procedure) and manual checks from shifters detect and flag new or temporary Tracker problems and classify each run according to hardware, reconstruction and calibration conditions give prompt feedback to Tracker experts about hardware Re-assess Tracker status using full The system was used during extensive cosmic data taking of CMS in Autumn 2008: → The Si. Strip DQM system demonstrated to have a flexible and robust implementation and has been essential to improve the understanding of the detector → It was possible to set up and test the first prototype of data certification procedure from results of Quality Tests (automatic → Enable any user to consult the certification results and select suitable runs for specific commissioning/physics analysis tasks L. Benucci, Data Quality Monitoring of the CMS Silicon Strip Tracker Detector, FRONTIER DETECTORS FOR FRONTIER PHYSICS, 24 -30/5/09 – Isola d'Elba - Italy The data quality is assessed through histograms (about 300, 000 histograms defined). They are organized in hierarchical tree like folder structure reflecting the tracker geometry and are filled accessing information from data at various levels of data reconstruction. Finally they are stored in Root files